London may have spent approximately $18 billion to host the Olympic Games, but money is already flowing back into the economy. According to Visa, cardholders spent nearly $700 million within opening week (July 23-July 29). And it’s not just how much they spent but where and how people spent. Turns out it’s not hotels, entertainment or airlines with the highest spend. Instead, it’s services.

From big purchases to small services, it’s crucial to watch how you spend money overseas. Hidden fees, currency exchange and creative pricing can all alter an international travel budget.

To win this week’s contest share your best advice on how travelers can save money when booking hotels, finding entertainment or purchasing goods and services overseas. If you want to take home the gold, don’t just tell us how to save money. Tell us how to avoid fees, take advantage of programs and perks, and find real travel value.

Leave your guesses in the comments to be eligible for a medal. Then on Thursday, August 7, we will announce our first three Olympians of Travel. Our medalists will win: